1. Field of the Invention
The present invention relates to a display device and a method of manufacturing a display device.
2. Description of the Related Art
Recently, display devices such as liquid crystal display devices and organic EL display devices using an organic EL (electro-luminescent) element have been put to practical use. However, an organic EL element is vulnerable to a water molecule, an oxygen molecule, etc., and therefore, there is a fear that an organic EL element is deteriorated to cause lighting failure such as a dark spot. Further, also in a liquid crystal display device, the properties of a thin film transistor vary due to the effect of penetrating water, and a problem arises that the display quality is deteriorated.
Therefore, for example, JP 2006-80094 A discloses a display device in which a calcium member having hygroscopicity is formed in a peripheral portion in a substrate plane on a glass substrate, and the calcium member is covered with an adhesive which bonds the glass substrate to a protective glass, whereby a water molecule is prevented from penetrating into a display region.
Further, for example, JP 2010-198926 A discloses a display device in which a polar material is provided between an element substrate on which a light-emitting element is to be formed and a sealing substrate to be bonded to the element substrate, and the polar material adsorbs a bubble contained in a sealing agent which bonds the two substrates, whereby the occurrence of a chemical reaction between the light-emitting element and an oxygen molecule or a water molecule contained in the bubble is prevented.
Further, JP 2002-8852 A discloses an organic EL display device which includes a sealing member formed so as to seal an organic EL layer, and in which a deoxygenation and dehydration section is formed at any position in a space sealed by the sealing member.
Further, JP 2013-110116 A discloses a display device in which a sealing substrate covering an electrode layer with an adhesive in an outer peripheral portion of a substrate is included, whereby water or the like is prevented from penetrating from the outside of the sealing substrate.
Further, JP 2008-77951 A discloses a display device in which a sealing material is applied to an outer periphery of a liquid-repellent frame body, and a layer containing a hygroscopic substance is made to face an organic EL element of a flat element substrate and bonded thereto, and then sealed by curing the sealing material, whereby water or the like is prevented from penetrating inside the frame body.